Paul Dalby

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Paul Dalby
Board Member, Water Industry Alliance In Fusion
Consulting
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Summary

• Demand for water in Adelaide is in danger of
  exceeding supply in short and long term
• Desalination is one supply option among many
• Independent of climate, greatest security
• Highest energy and financial cost
• Potential serious threat to marine habitat
• There are other options which have different
  costs and benefits

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Desalination

• 1. Distillation Processes
• 2. Membrane Processes
• Reverse Osmosis is a pressure driven process
  which forces saline water through a membrane,
  leaving salts behind.
• Electrodialysis is a voltage driven process and
  uses an electric potential to move salts
  selectively through a membrane, leaving fresh
  water behind.

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Reverse Osmosis
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Why did SA consider desalination?

• Water source independent of climate
• Demand exceeds supply from rainfall capture and
  river flow
• Cope with long droughts, climate change and
  increasing population
• Maintain economic activity and investor
  confidence in Adelaide
• Politics (many South Australians asked for it!)

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Desalination in Australia

• Currently only provides approximately 1 of
  Australias potable supply
• 17 of Perths potable supply (45GL)
• Energy supplied by wind power
• Second plant planned for 2011 (45GL)
• Most Australian capital cities are investigating
  or planning desalination plants to meet future
  needs
• Most of these are controversial

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Potential problems of desalination

• Impacts on marine environments
• Benign to catastrophic (other speakers)
• Cost (1.5B for Adelaide, up to 2/kL)
• Energy consumption and carbon emissions
• renewable energy options?

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Our current supplies

• First Use
• River Murray
• fine if we got our guaranteed supply
• Theoretically possible to buy and store all we
  need, even in very dry years
• Mount Lofty Ranges Catchments
• Unreliable
• Recycled
• Recycled sewage water for irrigation (30 in
  metro Adelaide, 24 in country)
• Aquifer storage and recovery for industrial use
  in Salisbury

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First Use Alternatives

• Demand management
• Plenty of potential
• Done well, social/economic benefit and vice versa
• Limited political support beyond low hanging
  fruit?
• Rain water harvesting
• gt50 households have rainwater tanks (highest in
  Aust)
• Theoretical potential of 5-100 of household use
• Similar life-time cost as desalination (borne by
  user)
• Some health concerns for potable use
• Rain gardens!
• Groundwater
• Not much chop in Adelaide, perhaps emergency use
  only

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Re-use alternatives

• Wastewater recycling
• Major health concerns for potable re-use
• Lots of opportunities for non-potable re-use
• In situ/distributed vs centralised
• Benefits to health of the Gulf
• Aquifer storage and recovery
• Difficult to store (a couple of big events
  annually)
• Long term storage management issues?
• Health concerns for potable re-use
• Benefits to health of the Gulf

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Energy intensity

• Most options require energy
• Desalination sea water (3 - 5 kWh per kilolitre
  highest)
• Brackish reverse osmosis (0.7-1.2 kWh)
• Pumping water from the River Murray (1 1.25
  kWh)
• Municipal wastewater reclamation (0.8 -1.0 kWh)
• Conventional water treatment (0.4 - 0.6 kWh)
• Infrastructure for rainwater harvesting (lt1 kWh)
• Non-potable use of waste and storm water (low)
• Demand management REDUCES energy use but there
  are potentially other costs

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Cost of desalination

• Energy inputs are 50 - 75 of costs
• Membrane filtration is most energy efficient but
  has higher start up costs
• Energy required is about 4.5 kWh per kilolitre
• The full cost of production is 1.70 to 2.00 per
  kL (operating and capital) for Adelaide plant
• We currently pay 0.71 - 1.65 per kL plus a
  fixed fee for water pumped to your house
• Current cost is of supply is 0.75 - 0.80

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Additional energy costs

• 4.5 kWh per kL
• 100 - 200 kL per capita per annum
• 25 supplied by desalination (50 GL)
• Attribute all energy costs
• 225 kWh per capita per annum
• Av. energy use in Australia is 11,000 kWh
• 2.0 increase in energy use

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Risk management

• Assuming we need to diversity our water supplies
• Do we need part of our supply to be independent
  of climate?
• How much risk to human health are we willing to
  accept?
• How much risk to environmental values are we
  willing to accept?
• If desalination can be carbon neutral, is that
  ok?
• How much are we be prepared to pay?

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Continuing the conversation

• (democracy)
• blog.litfuse.com.au
• You can respond directly or back-link your blog
• Put up data, comments, links, statements
• Talk to each other
• Invite experts to add their views

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Governance and Regulation

• There is a conflict between sound water
  management objectives and revenue raising
  objectives
• Buying and storing water from River Murray why
  not?
• Independent Regulator - NWI
• Deregulation (not privatisation) of water supply?
• Permission to capture rain water

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References

• Tennille Winter, David J. Pannell and Laura
  McCann. (2000) The Economics of Desalination and
  its Potential Application in Australia.
  Agricultural and Resource Economics, University
  of Western Australia, Perth, WA 6009, Australia
• Energy Equity. Preparing households for climate
  change efficiency, equity, immediacy. Australian
  Conservation Foundation (ACF), CHOICE and the
  Australian Council of Social Service (ACOSS)
• Australian water recycling today the big
  issues. John Radcliffe. National Water Recycling
  and Reuse 2008 Conference 27 May 2008
• Australian Bureau of Statistics
• Colin Creighton, CSIRO
• SA Water